Influence of an Inclined Cooling Plate on the Production of A356/CNF and A356/SiC MMC by Compocasting

2006 ◽  
Vol 519-521 ◽  
pp. 609-614
Author(s):  
R.G.S. Mussi ◽  
Tetsuichi Motegi ◽  
Fumi Tanabe ◽  
H. Kawamura ◽  
K. Anzai ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Melting Point ◽  
Sem Analysis ◽  
Copper Plate ◽  
Pouring Temperature ◽  
Cooling Plate ◽  
Separation Theory ◽  
The Matrix ◽  
Solidification Nuclei ◽  
Fluid Metal

The influence of an inclined cooling plate utilized as a modification in the compocasting process of aluminum alloy is studied in this paper. Based on the crystal separation theory, molten A356 is poured on the inclined copper plate in order to produce solidification nuclei inside the fluid metal, which is, then, mechanically stirred while reinforcement is added through its surface. Carbon nano fibers (CNF) and particulate SiC were utilized as reinforcement, in quantities varying from 0.5 to 15vol%. Dispersion of the reinforcements was observed by macro and microstructure analysis. For CNF, addition of quantities up to 1vol% resulted in homogeneous dispersion through the matrix, although SEM analysis showed the presence of clusters of up to 50μm in some points of the samples. SiC was properly mixed into matrix until 10vol%. Globular crystals were obtained, but some coarsening occurred, especially for small quantities of reinforcement. Utilization of the inclined cooling plate produced good inclusion and homogenization for two different reinforcements through an A356 matrix. The best results were obtained for a 180mm cooling plate, with inclination of 60o. The pouring temperature utilized was 10oC over the melting point of the alloy, and temperature of the tundish was kept around 598oC during stirring.

MICROSTRUCTURAL EVOLUTION OF Al-Cu-Mg-Ag ALLOY WITH TRACE Zr ADDITION DURING TWO-STEP HOMOGENIZATION

2009 ◽  
Vol 23 (06n07) ◽  
pp. 855-862 ◽  
Author(s):  
FEIYUE MA ◽  
ZHIYI LIU
Keyword(s):  
Melting Point ◽  
Grain Boundaries ◽  
Microstructural Evolution ◽  
Cast Alloy ◽  
Scanning Calorimetry ◽  
Zr Addition ◽  
Homogenization Time ◽  
The Matrix ◽  
Higher Temperature ◽  
Lower Temperature

The microstructural evolution in an Al - Cu - Mg - Ag alloy with trace Zr addition during homogenization treatment was characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS). It was shown that the low-melting-point phase segregating toward grain boundaries is Al 2 Cu , with a melting point of 523.52°C. A two-step homogenization process was employed to optimize the microstructure of the as-cast alloy, during which the alloy was first homogenized at a lower temperature, then at a higher temperature. After homogenized at 420°C for 6 h, Al 3 Zr particles were finely formed in the matrix. After that, when the alloy was homogenized at an elevated temperature for a longer time, i.e., 515°C for 24 h, most of the precipates at the grain boundaries were removed. Furthermore, the dispersive Al 3 Zr precipitates were retained, without coarsening greatly in the final homogenization step. A kinetics model is employed to predict the optimal homogenization time at a given temperature theoretically, and it confirms the result in present study, which is 420°C/6h+515°C/24h.

Effect of pouring temperature on A356-TiB2 MMCs cast in sand and permanent moulds by in-situ method

2016 ◽  
Vol 25 (5-6) ◽  
pp. 165-169
Author(s):  
C. Rajaravi ◽  
P.R. Lakshminarayanan
Keyword(s):  
Evaluation Studies ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
Matrix Composites ◽  
Structure Property ◽  
Pouring Temperature ◽  
Matrix Metal ◽  
Property Evaluation ◽  
The Matrix

AbstractThe paper describes a different condition of pouring temperature by sand and permanent mould to produce A356-6 wt% TiB2 metal matrix composites by in-situ method salt metal reaction route. The observation of SEM micrographs shows particle distribution of the TiB2 and it appears in hexagonal shape in Al matrix. The results of X-ray diffraction (XRD) analysis confirmed the formation of those TiB2 particulates and the results showed TiB2 particles are homogeneously dispersed throughout the matrix metal. Subsequent structure-property evaluation studies indicated sub-micron size reinforcement of in-situ formed TiB2 particles with improved physical and mechanical properties as compared to sand and permanent mould of Al-TiB2 composites. From, the permanent mould Al-TiB2 composite has an advantage of increase the properties over sand mould Al-TiB2 composite.

Small Lead and Indium Inclusions in Aluminium

1991 ◽  
Vol 235 ◽  
Author(s):  
E. Johnson ◽  
K. Hjemsted ◽  
B. Schmidt ◽  
K. K. Bourdelle ◽  
A. Johansen ◽  
...  
Keyword(s):  
Melting Point ◽  
Elevated Temperatures ◽  
Supersaturated Solution ◽  
In Situ Tem ◽  
Initial Growth ◽  
Heating And Cooling ◽  
Moiré Fringes ◽  
The Matrix ◽  
Spontaneous Phase

ABSTRACTIon implantation of lead or indium into aluminium results in spontaneous phase separation and formation of lead or indium precipitates. The precipitates grow in topotactical alignment with the matrix, giving TEM images characterized by moiré fringes. The size and density of the precipitates increase with increasing fluence until coalescence begins to occur. Implantations at elevated temperatures lead to formation of larger precipitates with well developed facets. This is particularly significant for implantations above the bulk melting point of the implanted species. Melting and solidification have been followed by in-situ TEM heating and cooling experiments. Superheating up to ∼ 50 K above the bulk melting point has been observed, and the largest inclusions melt first. Melting is associated with only partial loss of facetting of the largest inclusions. Initial growth of the inclusions occurs by trapping of atoms retained in supersaturated solution. Further growth occurs by coalescence of neighbouring inclusions in the liquid phase. Solidification is accompanied by a strong undercooling ∼ 30 K below the bulk melting point, where the smallest inclusions solidify first. Solidification is characterized by spontaneous restoration of the facets and the topotactical alignment.

scholarly journals Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites

2018 ◽  
Vol 18 (18) ◽  
pp. 18-23 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Tribological Characteristics ◽  
Volume Fractions ◽  
Sic Particles ◽  
The Matrix

Abstract Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.

scholarly journals Studi Fluiditas dan Karakteristik Aliran pada Pengecoran Al-Si Alloy Menggunakan Simulasi Numerik

2018 ◽  
Vol 1 (1) ◽  
pp. 007-012
Author(s):  
Andri Willy Adianta ◽  
Suprianto Suprianto ◽  
Arnius Daely ◽  
Mikael F. Bangun
Keyword(s):  
Aluminum Alloy ◽  
Flow Velocity ◽  
Computational Fluid Dynamic ◽  
Surface Defects ◽  
Fluid Dynamic ◽  
Liquid Aluminum ◽  
Flow Analysis ◽  
Pouring Temperature ◽  
Gravity Casting ◽  
Aluminum Castings

Aluminium silikon alloy merupakan paduan aluminium yang banyak digunakan dalam bidang teknik. Paduan ini memiliki kekuatan yang baik dan banyak diproduksi menjadi suatu komponen melalui proses pengecoran. Kandungan silikon dapat mengakibatkan penurunan fluiditas coran alumunium yang pada akhirnya akan menurunkan kualitas coran, fluiditas ini juga dipengaruhi temperatur pada saat penuangan alumunium cair. Penelitian ini bertujuan untuk mengetahui efek temperatur penuangan terhadap fluiditas, karakteristik aliran dan cacat coran pada pengecoran aluminium silikon alloy menggunakan cetakan pasir. Pengecoran dilakukan dengan gravity casting, analisa aliran simulasi meliputi distribusi kecepatan aliran, temperatur, tekanan, cacat permukaan dan fluiditas yang terjadi pada saat proses pengisian rongga cetak serta perbandingan fluiditas coran dan cacat permukaan pada eksperimental. Temperatur penuangan 685, 710, 735, 760 dan 785°C dengan ketebalan cetakan pola 1, 3, 5, 7, 9, dan 12 mm. Proses simulasi menggunakan software berbasis computational fluid dynamic. Hasil penelitian diperoleh temperatur tuang 785oC memiliki kecepatan aliran tertinggi yaitu sebesar ±0.145 m/s pada rongga 12 mm dan distribusi temperatur yang tinggi yaitu sebesar ±759 oC pada rongga 3 mm, sedangkan temperatur tuang 685oC memiliki distribusi tekanan yang tinggi yaitu sebesar ±107287 Pa pada rongga 6 mm. Cacat permukaan terbanyak pada temperatur tuang 785oC dan temperatur tuang 685oC paling sedikit. Fluiditas coran terbaik pada temperatur 785oC dimana rongga 12, 9, 7, 5 dan 3 mm terisi penuh dan 1 mm mencapai 181.4 mm.   Aluminum silicon alloy is an aluminum alloy that is widely used in engineering. This alloy has good strength and plenty of it are produced into a component through the casting process. Silicon content could result in a decrease in fluidity of aluminum castings which in turn would reduce the quality of casting. This fluidity is also influenced by temperature at the time of pouring liquid aluminum. This study aims to determine the effect of pouring temperature on fluidity, flow characteristics and casting defects on aluminum alloy silicon casting by using sand mold. Casting was conducted by gravity casting, simulation flow analysis including flow velocity distribution, temperature, pressure, surface and fluidity defects that occured during the process of filling the mold cavity as well as the comparison of the fluidity of castings and surface defects in the experiment. Casting temperatures was 685, 710, 735, 760 and 785°C with a mold thickness of patterns 1, 3, 5, 7, 9 and 12 mm. The simulation process used software based on computational fluid dynamic. The result showed pouring temperature of 785oC had the highest flow velocity of ± 0.145 m/s in 12 mm cavity and a high temperature distribution of ± 759oC in cavity of 3 mm, while the pouring temperature of 685oC had a high pressure distribution of ± 107287 Pa in 6 mm cavity. Most surface defects occurred at pour temperature of 785oC and the least at pour temperature of 685oC. The best castings liquidity occurred at temperature of 785oC where the cavity of 12, 9, 7, 5 and 3 mm was fully filled and 1 mm reached 181.4 mm.

Effect of Residual Aluminum Thickness on Microstructure and Strength of Friction Stir Spot Welded Aluminum Alloy/Copper Lap Joint

2021 ◽  
Vol 1042 ◽  
pp. 3-8
Author(s):  
Mitsuhiro Watanabe ◽  
Shinpei Sasako
Keyword(s):  
Aluminum Alloy ◽  
Pure Copper ◽  
Optical Microscope ◽  
Copper Plate ◽  
Laminate Structure ◽  
Alloy Plate ◽  
Friction Stir ◽  
Residual Aluminum ◽  
Welding Interface ◽  
Aluminum Alloy Plate

Dissimilar metal lap joining of A5052 aluminum alloy plate and C1100 pure copper plate was performed by using friction stir spot welding. The rotating welding tool, which was composed of a probe part and a shoulder part, was plunged from the aluminum alloy plate which was overlapped on the copper plate, and residual aluminum alloy thickness under the probe part of the welding tool after plunging of the welding tool was controlled in the range from 0 mm to 0.4 mm. The strength of the welding interface was evaluated by using tensile-shear test. Microstructure of the welding interface was examined by using an optical microscope and a field emission scanning electron microscope. The welding was achieved at the residual aluminum alloy thickness under the probe part of the welding tool below 0.3 mm. The welded area was formed at aluminum alloy/copper interface located under the probe part of the welding tool, and its width increased with decreasing the residual aluminum alloy thickness. A characteristic laminate structure was produced in the copper matrix near the welding interface. In the joint fabricated at the residual aluminum alloy thickness below 0.1 mm, hook of Cu was formed at edge of the welded area. The fracture did not occur at the welding interface. A remarkable improvement in strength was observed in the joint fabricated at the residual aluminum alloy thickness below 0.1 mm. The formation of laminate structure and hook is considered to result in joint strength improvement.

Numerical Simulation of Casting Deformation and Stress of A356 Aluminum Alloy Thin-Walled Frame Casting

2021 ◽  
Vol 1033 ◽  
pp. 24-30
Author(s):  
Yi Dan Zeng ◽  
Li Tong He ◽  
Jin Zhang
Keyword(s):  
Aluminum Alloy ◽  
Casting Process ◽  
Mold Temperature ◽  
Hot Cracking ◽  
Thin Wall ◽  
A356 Aluminum Alloy ◽  
Pouring Temperature ◽  
Thin Walled ◽  
Alloy Castings ◽  
A356 Aluminum

One of the main reasons for the scrap of cast thin-wall frame aluminum alloy castings is deformation and cracking. It is an effective method for solving the problem by predicting the distribution of casting stress, clarifying the size of the deformation and the location of the crack, and taking necessary measures in the process. This paper uses the ProCAST software to simulate the thermal stress coupling of A356 thin-walled frame castings, analyzes the influence of pouring temperature, pouring speed and mold temperature on the stress field distribution of castings, predicts the hot cracking trend and deformation, and optimizes Casting process..

scholarly journals Optimizing The Addition of TiB to Improve Mechanical Properties of the ADC 12/SiC Composite Through Stir Casting Process

2019 ◽  
Vol 130 ◽  
pp. 01005
Author(s):  
Cindy Retno Putri ◽  
Anne Zulfia Syahrial ◽  
Salahuddin Yunus ◽  
Budi Wahyu Utomo
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Aluminum Alloy ◽  
Casting Process ◽  
Stir Casting ◽  
Automotive Application ◽  
Alloying Element ◽  
Brake Shoe ◽  
The Matrix

The goal of this research is to improve the mechanical properties such as strength, hardness and wear resistance for automotive application such as brake shoe and bearings due to high cycle, load and impact during their usage. Therefore, another alloying element or reinforcement addition is necessary. In this work, the composites are made by ADC 12 (Al-Si aluminum alloy) as the matrix and reinforced with micro SiC through stir casting process and TiB is added various from (0.04, 0.06, 0.15, 0.3 and 0.5) wt.% that act as grain refiners and 5 wt.% of Mg is added to improve the wettability of the composites. The addition of TiB improves the mechanical properties because the grain becomes finer and uniform, and the addition of Mg makes the matrix and reinforce have better adhesion. The results obtained that the optimum composition was found by adding 0.15 wt.% of TiB with tensile strength improve from 98 MPa to 136.3 MPa, hardness from 35 to 53 HRB and wear rate reduced from 0.006 2 mm3 s−1 to 0.002 3 mm3 s−1 respectively.

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